This subproject is one of many research subprojects utilizing the resources provided by a Center grant funded by NIH/NCRR. Primary support for the subproject and the subproject's principal investigator may have been provided by other sources, including other NIH sources. The Total Cost listed for the subproject likely represents the estimated amount of Center infrastructure utilized by the subproject, not direct funding provided by the NCRR grant to the subproject or subproject staff. EmrE is a small multidrug resistance transporter that couples proton import to polyaromatic cation export in E. coli, thus conferring resistance to drugs of this type. The goal of this project is to understand how this secondary active transport protein acts on a molecular level. This requires detailed structural knowledge coupled with dynamic information, including the timescale, amplitude and direction of structural changes. As an integral membrane protein, secondary active transporters of this type are a challenge to work with. Our previous attempts to assign the backbone amide resonances were hampered by the very dynamics that make this protein interesting. We have now developed a new bicelle solubilization protocol and optimized lipid composition to reduce dynamics and facilitate assignment. These assignments will be critical for further interpretation of our dynamics data and structure determination.